Just keep in mind that any guns you bring into the US you won't be able to get back into Canada on your return. So it would make more sense to leave the expensive guns in Canada and getting equipped with their cheap guns down there, and then getting rid of those in the US before coming back to Canada.

But yeah, it's been covered. If you want to bring an airsoft gun into the US, make sure it has a blaze orange tip, as that's one of the requirements for importation into the US.